The group, which includes various public-sector workers, held red boxes similar to the one Mr Darling will use for Wednesday’s budget.

Pensioner Sheila Skinner and teenager Adam Holmes were among the campaigners.

Ms Skinner explained why she was taking part.

“I am a pensioner and, when we started, my husband and I had very little but we never spent what we didn’t have,” she said.

“I wanted to be there to explain things to our children and that has affected my pension now.

“As for Trident, it is evil and nothing but a waste when you think of all that’s needed on the earth.”

Mr Holmes added: “I wanted to learn carpentry and joinery and I got a job labouring with a building firm. They were going to give me an apprenticeship after a year, but then the credit crunch came along and they were laying guys off instead.”